Disconnect switches and air switches are two common switching devices in power systems, which differ in application scenarios and working principles. The following will introduce the definition, function, structure, working principle, application areas and other aspects of the disconnecting switch and air switch in detail.
I. Disconnect Switch
Definition
Disconnect switch is a switching device used to separate and isolate electrical equipment. It is mainly used in the power system to cut off the power supply to energized equipment, overhaul and maintenance to ensure the safety of operators. Disconnect switch has the characteristics of standardization, high reliability and flexible operation.
Functions
The main functions of the disconnecting switch are as follows:
(1) Cutting off power supply: When it is necessary to repair, overhaul or remove the equipment, the equipment can be completely isolated from the power supply by the disconnecting switch to ensure the safety of the operators.
(2) Isolating equipment: the disconnecting switch can isolate the equipment from other equipment, avoiding the interference between the equipment and ensuring the normal operation of the power system.
Structure
The disconnecting switch is generally composed of manipulating mechanism, disconnecting, fixing mechanism, contacts and other components. The specific structure has different forms such as single-knife double-break type, double-knife double-break type, three-knife double-break type and so on.
Working principle
The working principle of disconnecting switch is relatively simple. When the handle or manipulating mechanism rotates, it makes the disconnections separate or close, realizing the isolation of equipment or power supply.
Fields of application
Disconnect switches are mainly used in high-voltage power systems, such as substations, transmission lines and so on. It is widely used to switch the power supply, sectional isolation equipment, to ensure the safety of equipment maintenance, maintenance and operation.
Air switch
Definition
Air switch is a kind of electrical equipment that uses gas as medium for switching operation. It is mainly used for opening and closing circuits, controlling the power supply on and off, and playing the role of overload and short-circuit protection. Air switch is characterized by high reliability, strong durability and strong resistance to environmental influence.
Functions
The air switch mainly has the following functions:
(1) Opening and closing circuits: by controlling the state of the switch, it realizes the on-off control of the power supply.
(2) Overload protection: When the current in the circuit exceeds the rated value, the air switch can quickly cut off the power supply to avoid circuit overload damage.
(3) Short-circuit protection: When a short-circuit accident occurs in the circuit, the air switch can quickly cut off the power supply to avoid the safety hazard caused by the short-circuit.
Structure
Air switches are generally composed of contact system, spring mechanism, electromagnetic excitation system, arc extinguishing chamber and other parts. Some air switches also include current transformer and current transformer output interface.
Working Principle
The working principle of air switch is to utilize the gas breakdown and arc extinguishing characteristics. When the current in the circuit exceeds the rated value, the electromagnetic excitation system will cause gas breakdown, forming a low impedance path to realize the short circuit protection of power supply.
Fields of application
Air switches are mainly used in low-voltage power systems, such as low-voltage distribution rooms, factories, homes and so on. It is widely used for electrical energy load opening and closing control, overload protection and short-circuit protection to ensure the normal operation of the circuit and personal safety.
Summarize:
Disconnect switches and air switches differ significantly in terms of definition, function, structure, working principle and application areas.
Disconnect switches are mainly used to separate and isolate equipment and power supply, and ensure the safety of operators, applied to high-voltage power systems. The air switch is mainly used for opening and closing circuits, controlling the on-off of the power supply as well as overload and short-circuit protection, and is applied to low-voltage power systems.
